In situ analysis of copper electrodeposition reaction using unilateral NMR sensor

Monitoring Electrochemical Reactions in Situ with Low Field NMR: A Mini-Review

“…The linear relationship between the relaxation rate (1 T 2 ) and the concentration of paramagnetic ions has been exploited to quantify paramagnetic ions in solutions, to calculate K SP values [23], to study coordination complexes with paramagnetic ions as ligands [24] and also to monitor electrochemical reactions in situ [8,9].…”

“…This force can alter the morphology of metallic deposits as well as contribute to the magnetic agitation of the solution. In 2015, Gomes et al [9] again showed that it is possible to follow the electrochemical deposition of copper ions, this time using a unilateral, homebuilt, sensor. To do this, however, a Faraday cage was built around the system to isolate it from ambient radio-frequencies which are driven into the NMR detection region by the electrodes and completely destroy the NMR signal.…”

“…The instruments used for these analyses are normally based on permanent magnets which produce a magnetic field intensity usually below 0.6 T (25 MHz for 1 H) with a low homogeneity (above 100 ppm) which means that the relevant information can only be extracted from the intensity of the free induction decay signal (FID), the spin echo or by measuring the relaxation times T 1 and/or T 2 or the diffusion coefficient of the sample. In this review we show the application of time domain NMR (TD NMR-also known as low-field NMR) to an increasingly popular research field which is the in situ monitoring of electrochemical reactions (EC-NMR) [7][8][9]. The first published paper which detailed the use of TD NMR for such an application was published as recently as 2010 [10] (which is a 40 year delay from the first paper detailing the use of high-field NMR for the same application [11]).…”

Desenvolvimento de um sensor de RMN (ímã e sonda) para aplicações espectroeletroquímicas

“…In 2015 Gomes et al (19) again verified the same pattern of increased electrochemical reaction rates when in the presence of a magnetic field. This time, however, they used a unilateral NMR sensor (using a stray-field magnet which will be briefly discussed in Section 1.3.2.1).…”

“…The results from Gomes et al in 2014 and 2015 (7,19) show that performing an electrochemical reaction in the presence of the magnetic field, B, of the NMR spectrometer is not quite the same as performing it in the absence of B. The reason for this is the magnetoelectrolysis effect which is known to stir the solution and increase the quantity of ions that reach the surface of the electrode, thus accelerating the reaction.…”